Blenders are used to smash and squeeze fruits. A conventional blender may include a single shaft to which a single stirring blade is attached. When the blender operates, food rotates in the same direction as the stirring blade. This may reduce the blender's effect and efficiency. A conventional blender may include a single shaft to which two stirring blades are attached. Such blenders generally have round containers. When such a blender is in operation, planes constituted by the two stirring blades do not meet the shapes of the container, resulting in more dead angles than blenders having a single stirring blade. As a consequence, the stirring effect and efficiency is decreased.